Twenty years ago our fall foliage reached its peak around October 15 but today — only one day before the 15th — the leaves have just begun to change. We had the same situation last year as shown in my photo taken at Moraine State Park on 15 October 2017.

Delayed timing makes it hard to know when fall color will reach its peak but the Pennsylvania Bureau of Forestry (DCNR) is here to help. Check out their Fall Foliage Guide complete with an interactive map and weekly reports. The October 11-17, 2018 forecast map is shown below (yellow means “approaching best color”). Click here or on the caption to see the full report.

I’m pretty good at identifying western Pennsylvania’s deciduous trees because I live with them, but evergreens aren’t common here and they confuse me.

After I flunked the spruce-fir-hemlock test in Newfoundland in July I vowed to learn from that experience and do better last month in Maine. I updated my conifer “cheat sheet” and memorized the difference between balsam firs and hemlocks.

Conifers are still confusing but I’m doing better. I got a B- in Maine.

How do you tell the difference between pines, spruces, firs and hemlocks? Learn from my conifer cheat sheet: In A Coniferous State.

(photo from Wikimedia Commons; click on the caption to see the original)

Yesterday morning this oak was intact as we searched it for warblers in Schenley Park. Last evening three Duquesne Light trucks were parked below it, fixing the wires it hit when a big chunk fell on Bartlett Street.

Here’s what broke (photo below). Most of the tree still stands but I wouldn’t be surprised if DPW chops it down now that it “misbehaved.”

If this stump was damp on a warm, very dark night (impossible in Schenley Park) the fungus would glow in the dark — a phenomenon called foxfire.

We usually don’t know that a tree is infected but the fungus will give us a hint this month. Armillaria produces fruit in autumn that we call honey mushrooms. (Here’s a USDA photo of one species, Armillaria tabescens.)

If you find honey mushrooms at the base of a tree, that tree is infected.

Unfortunately there’s a lot of Armillaria in Schenley Park. I’ll look for mushrooms this month to find out who’s in trouble.

NEWS about the Bartlett tree: The branch that fell on Bartlett Street was hollow — probably not Armillaria but it was bad nonetheless. Here’s a photo of the thickest part of the branch after it was chopped up.

Native to the Appalachians, Allegheny and Cumberland Plateaus, the cucumber magnolia (Magnolia acuminata) produces an unusual fruit that starts out green, ripens to dark pink, then its red-orange seeds pop out. (The one on the right isn’t fully ripe yet.)

When the fruit falls in autumn it’s quickly gathered by squirrels and chipmunks. You’ll find the ones they miss on the forest floor.

Gray squirrels build leaf nests high in the trees for shelter in winter, nests for their young, and for sleeping at night. The outer layer is composed of leaves and twigs that make a water resistant blob about the size of a beach ball. The inside is lined with moss, grass, shredded bark and other soft vegetation. The entrance faces the trunk.

Squirrel nests can be as much as 70 feet off the ground. Here’s what one looks like.

Gray squirrel nest (photo by Marcy Cunkelman)

To gather building materials, the squirrel gnaws near the branch tip — often an oak — until the spray of leaves comes loose. If he isn’t careful to hold the twig, it falls. Oh well. The squirrel gnaws another one.

You can tell when a spray of leaves is a squirrel’s handiwork. The tip of the twig looks chiseled. Teeth made this mark!

Tip of a white oak twig chiseled by a squirrel (photo by Kate St. John)

Last week I found many leafy twigs on the trails in Pittsburgh. After four days of cold rain the squirrels were making nest repairs.

As winter approaches you’ll find them, too. The squirrels are fortifying their nests and they don’t have much time. The leaves will be gone in November.

(photos by Kate St. John, Marcy Cunkelman and from Wikimedia Commons; caption has a link to the original)

The fruit is sweet like mango with a creamy texture like ripe banana. Despite its sweet addictive flavor, pawpaws aren’t in widespread commercial production because the fruit is so ephemeral. Some would say it’s finicky.

Pawpaws ripen only once a year — in September.

They ripen only on the tree. They can’t be picked in advance.

The fruit bruises so easily it has to be shipped in expensive padded packaging.

In the old days, people would gather fallen pawpaws as they walked in the woods in September. This practice eventually disappeared and most people forgot about the fruit until a dedicated group of pawpaw enthusiasts and Andrew Moore’s 2015 book, Pawpaw, made it better known.

Want to taste a pawpaw? The best place to do it is at a pawpaw festival. Eat them raw or in ice cream, pies, popsicles, and even beer!

There are three pawpaw festivals within driving distance of Pittsburgh.